1. Technical Field
The present invention relates to a vehicle occupant protection apparatus including an inflatable occupant protection device, such as an air bag. In particular, the present invention relates to an air bag module in which inflation fluid is selectively vented from a housing of the module in order to control the deployment of the air bag.
2. Description of the Prior Art
It is known to inflate an air bag to help protect a vehicle occupant in the event of sudden deceleration such as occurs in a vehicle collision. The air bag is stored in a deflated condition in a housing. An inflator, when actuated, provides a large volume of inflation fluid to inflate the air bag into a position to help protect the vehicle occupant.
Under normal circumstances, substantially all of the inflation fluid from the inflator is directed into the air bag to inflate the air bag. In some circumstances, however, it may be desirable to control or limit the amount of inflation fluid directed into the air bag. For example, if a vehicle collision occurs at a low speed, then it may be desirable to reduce the speed and force with which the air bag inflates. It is known to vent inflation fluid from the housing of an air bag module in such circumstances, so that less inflation fluid is directed into the air bag.
The present invention is a vehicle occupant protection apparatus including a sensor for sensing a vehicle crash. An inflatable vehicle occupant protection device has a deflated condition and an inflated condition for helping to protect the vehicle occupant. An inflation fluid source is actuatable to provide inflation fluid to inflate the inflatable device. A housing directs inflation fluid under pressure from the inflation fluid source toward the inflatable device upon actuation of the inflation fluid source. The housing has at least one burst panel attached to the housing. Initiating means, when actuated, enables the at least one burst panel to detach from the housing to a condition spaced apart from the housing to enable flow of inflation fluid out of the housing through a vent opening in the housing.
In one embodiment, the vehicle occupant protection apparatus includes an inflatable vehicle occupant protection device having a deflated condition and an inflated condition for helping to protect the vehicle occupant. An inflation fluid source is actuatable to provide inflation fluid to inflate the inflatable device. A structure provides an opening for enabling flow of inflation fluid away from the inflatable device. The structure has at least one burst panel with a first condition closing the opening and a second condition spaced apart from the structure and enabling flow of inflation fluid through the opening. An initiating means, when actuated, enables the burst panel to move from the first condition to the second condition to enable flow of inflation fluid through the opening.